The concept of using two pins or posts mounted on a router base to make a self-centering mortising and slotting base is per se well known. Spielman in his book "Router Jigs & Techniques" (1988 Sterling Publishing Co., Inc. New York N.Y.) describes such a base on page 202. A more recent application of the concept is described by Taylor and McDaniel in U.S. Pat. No. 5,423,360 where an apparatus for centering a work-piece relative to a cutting tool is disclosed. That concept could be adapted directly to a router table T, with a router (not shown) mounted to a base plate 14 (or a table for other tools such as drills, shapers etc.) as illustrated in FIG. 1 herein (Prior Art).
Thus, two posts 13a and 13b could be fixed to a table with pivots 12a and 12b, the posts being centered on each side of the cutting tool on a line through the center of the cutting tool 15. The posts could be, for example, four inch diameter disks cut from three-quarter inch stock. Although the arrangement illustrated in FIG. 1 could work for centering a work-piece it would be difficult to use and not truly practical. However, with certain unique modifications described hereinafter, such a device can be very useful not only for centering the workpiece but also in setting up the fence of a router table to perform various cuts.